un·​treat·​ed | \ˌən-ˈtrē-təd \

Definition of untreated 

: not treated untreated wastewater especially : not improved or controlled medically an untreated case of pneumonia untreated diabetic patients

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Synonyms & Antonyms for untreated


crude, native, natural, raw, rude, undressed, unprocessed, unrefined


dressed, processed, refined, treated

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Examples of untreated in a Sentence

Recent Examples on the Web

If left untreated, babies may develop cataracts, deafness, seizures or death. Alexandria Hein, Fox News, "Syphilis cases up 44 percent in California county," 18 Sep. 2018 Between 2000 and 2014, public health officials in 35 states, plus Guam, reported a total of 140 disease outbreaks associated with swimming in untreated recreational waters — mainly at beaches and bodies of water in public parks, the report says. Jamie Ducharme, Time, "Why July Is the Most Dangerous Month To Go Swimming," 28 June 2018 But there have been serious times such as the Flint water crisis, which took place when an emergency manager appointed by Snyder was in charge and the city in 2014 converted from Detroit water to untreated Flint River water in 2014. Carol Cain, Detroit Free Press, "Sue Snyder: What it's like to be Michigan's first lady," 23 June 2018 If untreated, the illness may last more than a month and could continue over a recurring cycle, health officials said. Rick Barrett, Milwaukee Journal Sentinel, "Cyclospora illness outbreak tied to Kwik Trip vegetable trays grows in Wisconsin and Minnesota," 15 June 2018 There were also three cases of Rocky Mountain spotted fever, which in severe cases can lead to limb amputation, hearing loss, paralysis and mental disability if left untreated. Thomas Leavy, CBS News, "Maine on the lookout for ticks that cause red-meat allergy," 25 June 2018 Dice said people will create new roads or hiking trails which, if left untreated, will become established areas where people will drive and hike through sensitive areas. J. Harry Jones, sandiegouniontribune.com, "Only 4 rangers patrolling 1,000-square-mile Anza-Borrego desert," 17 June 2018 Lasik can also interfere with the detection of glaucoma, or the buildup of pressure within the eye that, if left untreated, can lead to blindness. Author: Roni Caryn Rabin, Anchorage Daily News, "Blurred vision, burning eyes: This is a Lasik success?," 12 June 2018 Lasik can also interfere with the detection of glaucoma, or the buildup of pressure within the eye that, if left untreated, can lead to blindness. New York Times, "Blurred Vision, Burning Eyes: This Is a Lasik Success?," 11 June 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'untreated.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of untreated

15th century, in the meaning defined above

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Statistics for untreated

Last Updated

16 Nov 2018

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Time Traveler for untreated

The first known use of untreated was in the 15th century

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More Definitions for untreated


un·​treat·​ed | \-ˈtrēt-əd \

Medical Definition of untreated 

: not subjected to treatment an untreated disease

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More from Merriam-Webster on untreated

Thesaurus: All synonyms and antonyms for untreated

Spanish Central: Translation of untreated

Nglish: Translation of untreated for Spanish Speakers

Comments on untreated

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noxious or harmful

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